KATE KELLAND ONE of the Oxford scientists who co-developed AstraZeneca's COVID-19 vaccine defended its safety on Friday and said he was not worried that some countries had opted to restrict its use amid concerns about a possible link to very rare side effects. Adrian Hill, director of the Oxford University's Jenner Institute, said teams around the world were working to pin down any potential mechanism for what might be causing the blood clots, using real world data now so many shots have been administered. He agreed with medicines regulators in Britain, and Europe, and with World Health Organization experts, that…